Biliary laser lithotripsy.

Laser lithotripsy is an excellent method of fragmenting those biliary stones that cannot be removed easily by less technically advanced methods such as basket extraction. The energy can be delivered through fine flexible fibers, around 200 to 320 microns in diameter, that can be passed through the channels of a variety of small endoscopes. Currently, the optimal laser seems to a pulsed system because of the conversion of light to acoustic energy with minimal heating of the surrounding tissues, thus avoiding the chance of tissue injury and perforation. The best wavelength seems to be 504 nm, because at this wavelength, there is maximum absorption of laser energy by pigment stones, resulting in fragmentation using low-energy pulses. With further research, optimal wavelengths and pulse durations may emerge.